1. Field of the Invention
The present invention is in the field of railroad right-of-way maintenance. More particularly, the invention relates to apparatus and a method for removing old broken or rotted ties from beneath railroad rails and inserting a new tie in place of the old, with minimum manual labor and maximum efficiency.
2. Description of Prior Art
Railroad right-of-way maintenance has historically been a labor intensive activity. Large crews with picks, shovels, axes, crowbars and sledge hammers doing demanding and tedious manual labor have characterized the work of both right-of-way preparation and track laying, and maintenance for many years. In roughly the last thirty years machines have been designed and built to remove much of the hand labor from various railroad right-of-way activities, including machines for the removal and replacement of old ties.
The earliest known disclosure of such apparatus is Burk (U.S. Pat. No. 1,015,475). More recent U.S. Pat. Nos. including Fox (2,828,699), Kershaw (2,908,228), Perazzoli (3,000,325), Blix, Jr. et al. (3,294,033), Moorehead, jr. et al. (3,314,374), Kershaw (3,675,580), Peppin et al. (3,698,324), Holley et al. (3,780,664) and Dieringer et al. (3,964,397), also disclose such apparatus.
While these patents teach the mechanical removal and replacement of old ties from beneath the rails, and disclose apparatus that eliminates much of the manual labor, each prior art patent requires that the old tie be removed in one operation and the new tie inserted in another distinct operation. The two operations are not consecutive or reciprocal. Typically, the prior art apparatus requires a separate handling of the old tie, on the one hand, and the new tie, on the other hand, often with separate machines and separate crews. The prior art apparatus thus requires two separate gripping operations and two passes of the machinery, one for removing the old tie and the other for inserting the new tie. Thus two passes and four strokes per tie replaced are required in order to remove and discard the old tie and pick up and insert the new tie. More particularly, the withdrawal and insertion strokes required in the prior art are pulling the old tie along its longitudinal axis from beneath the rail (stroke one) and discarding or releasing it, returning to grasp a new tie located on the apparatus or the rails transversely above the old tie (stroke two), gripping the new tie and moving it transversely along its longitudinal axis to a position off to the side of the rails (stroke three), and then inserting the new tie beneath the rails by moving it once again in a path along its longitudinal axis to replace the old tie with the new (stroke four).
The disadvantage in the prior art is the time required to carry out two separate removing and replacement operations. Another disadvantage of prior art apparatus such as Peppin et al. (U.S. Pat. No. 3,698,324) and Holley et al. (U.S. Pat. No. 3,780,604) is that the old tie cannot be released or discarded sufficiently remote from the rails to be well out of the path of the new tie as it is inserted into the position of the old tie, to thereby replace the old tie.